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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 18 |
| 3 | 250 |
| 4 | 1372 |
| 5 | 13310 |
| 6 | 30758 |
| 7 | 117912 |
| 8 | 205770 |
| 9 | 535348 |
| 10 | 1707230 |
| 11 | 2383280 |
| 12 | 5774442 |
| 13 | 9648940 |
| 14 | 12244078 |
| 15 | 19103432 |
| 16 | 34837218 |
| 17 | 59559910 |
| 18 | 70364110 |
| 19 | 112485362 |
| 20 | 150322620 |
| 21 | 172723548 |
| 22 | 256380280 |
| 23 | 328205738 |
| 24 | 465279540 |
| 25 | 715535632 |
| 26 | 875755850 |
[2,18,250,1372,13310,30758,117912,205770,535348, 1707230,2383280,5774442,9648940,12244078,19103432, 34837218,59559910,70364110,112485362,150322620, 172723548,256380280,328205738,465279540,715535632, 875755850] |